At present, owing to the growth of electronic communication industries, user devices such as mobile communication terminals (cellular phones), electronic schedulers, personal complex terminals and the like are becoming necessities to modern society while becoming a significant means of delivery of rapidly changing information. Also, the user devices can be changed into multimedia communication devices in view of a function providing various kinds of data transmission services and various supplementary services as well as a voice call service. Also, a user device with a touchscreen is being commercialized, and even a User Interface (UI) technology of controlling the user device is continuously being developed along with the growth of services capable of being provided through the user device. Commonly, the user device has a microphone which converts a sound into an electrical signal and is used for a call, voice recording and the like.